Visceral Adiposity Independently Predicts Time to Flare in Inflammatory Bowel Disease but Body Mass Index Does Not

Unravelling the Relationship Between Obesity and Inflammatory Bowel Disease

Mirroring the global obesity epidemic, obesity rates in inflammatory bowel disease (IBD) patients is rising. Several epidemiological studies propose that 15%-40% of adult patients with IBD are obese, and an additional 25%-40% fall into the overweight category. This article examines the pathophysiologic relationship between obesity and IBD concerning the role of visceral adipose tissue, microbiota shifts, dietary patterns, and hunger hormone changes. Additionally, increasing evidence is demonstrating the negative impact that obesity is having on disease course and quality of life in patients with IBD. Obesity has been demonstrated to be associated with an attenuated response to immunomodulators and biological agents, as well as higher rates of peri-operative surgical complications. A better understanding of the relationship between obesity and IBD can be applied to clinical decision-making in personalizing treatment plans, promoting weight loss in patients with obesity, and identifying areas of future research.

A New Nomogram for Predicting Early Weight Loss Outcomes in Patients with Obesity Following Laparoscopic Sleeve Gastrectomy

PURPOSE

Laparoscopic sleeve gastrectomy (LSG) is an effective treatment for obesity, but early weight loss outcomes vary owing to individual nutritional and metabolic differences. We developed a nomogram model to predict early weight loss after LSG, incorporating computed tomography (CT)-based body composition metrics and preoperative inflammatory-nutritional markers.

METHODS

We retrospectively analyzed 305 patients with obesity who underwent LSG at the Affiliated Hospital of Qingdao University between January 2016 and June 2023. An external validation cohort of 105 patients from a separate institution was also included. Patients were categorized into optimal remission (%total weight loss [%TWL] ≥ 25%) and suboptimal remission (%TWL < 25%) weight loss groups one year postoperatively. Predictive variables were identified using Least Absolute Shrinkage and Selection Operator (LASSO) regression and multivariate logistic regression. A nomogram was constructed based on the significant predictors. Model performance was assessed using the area under the receiver operating characteristic curve (AUC), calibration curves, decision curve analysis (DCA), and clinical impact curve (CIC).

RESULTS

Independent predictors of suboptimal remission included BMI > 40 kg/m2, elevated total cholesterol, high neutrophil-to-lymphocyte ratio, high cortisol, low skeletal muscle index, and elevated visceral-to-subcutaneous adipose tissue area ratio. The constructed nomogram demonstrated strong predictive performance, with AUCs of 0.864 and 0.842 in the training and external validation cohorts, respectively. Calibration curves indicated excellent agreement between predicted and observed outcomes. DCA and CIC confirmed the model's clinical utility in both cohorts.

CONCLUSION

The developed nomogram effectively predicts early weight loss outcomes after LSG, supporting targeted perioperative management and personalized nutritional interventions.

Epidemiology, pathogenesis, diagnosis, and treatment of inflammatory bowel disease: Insights from the past two years

ABSTRACT

Inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, is a chronic inflammation of the gastrointestinal tract with unknown etiology. The cause of IBD is widely considered multifactorial, with prevailing hypotheses suggesting that the microbiome and various environmental factors contribute to inappropriate activation of the mucosal immune system in genetically susceptible individuals. Although the incidence of IBD has stabilized in Western countries, it is rapidly increasing in newly industrialized countries, particularly China, making IBD a global disease. Significant changes in multiple biomarkers before IBD diagnosis during the preclinical phase provide opportunities for earlier diagnosis and intervention. Advances in technology have driven the development of telemonitoring tools, such as home-testing kits for fecal calprotectin, serum cytokines, and therapeutic drug concentrations, as well as wearable devices for testing sweat cytokines and heart rate variability. These tools enable real-time disease activity assessment and timely treatment strategy adjustments. A wide range of novel drugs for IBD, including interleukin-23 inhibitors (mirikizumab, risankizumab, and guselkumab) and small-molecule drugs (etrasimod and upadacitinib), have been introduced in the past few years. Despite these advancements, approximately one-third of patients remain primary non-responders to the initial treatment, and half eventually lose response over time. Precision medicine integrating multi-omics data, advanced combination therapy, and complementary approaches, including stem cell transplantation, psychological therapies, neuromodulation, and gut microbiome modulation therapy, may offer solutions to break through the therapeutic ceiling.

Obesity Is Associated With Worsened Outcomes in Patients With Ulcerative Colitis on Advanced Therapies: A Propensity Matched Cohort Study From the U.S

BACKGROUND

Obesity has been linked to a more severe phenotype in patients with ulcerative colitis (UC).

AIM

To evaluate the impact of obesity on outcomes of advanced therapies in UC.

METHODS

We conducted a retrospective cohort study utilising the TriNetX database comparing the composite score of corticosteroid use, change in advanced therapy or colectomy within two years between two cohorts of patients with UC-those with obesity (BMI ≥ 30 kg/m2) and those without (BMI 18.5-24.9). The risk assessment was stratified to specific advanced therapies, including tumour necrosis factor α inhibitors (TNFi), vedolizumab, ustekinumab and Janus kinase inhibitors (JAKi). We performed 1:1 propensity score matching (PSM) for demographics, co-morbid conditions, laboratory values and IBD medications including corticosteroids.

RESULTS

There were 3904, 2025, 1150 and 477 patients on TNFi, vedolizumab, ustekinumab and JAKi, respectively, in the UC obesity cohort. After PSM, the UC obesity cohort was at an increased risk of the composite outcome of corticosteroid use, change in therapy and colectomy compared to the UC control cohort in patients on TNFi (aHR 1.37, 95% CI 1.29-1.49), vedolizumab (aHR 1.29, 95% CI 1.16-1.43), ustekinumab (aHR 1.1.26, 95% CI 1.10-1.44) and JAKi (aHR 1.38, 95% CI 1.13-1.69). Sub-group analysis based on the specific TNFi also showed an increased risk of composite outcome for infliximab (aHR 1.36, 95% CI 1.22-1.52) and adalimumab (aHR 1.26, 95% CI 1.11-1.42) within 2 years.

CONCLUSIONS

Obesity is associated with lower efficacy of several advanced therapies in patients with UC.

Modifiable Factors Influencing Disease Flares in Inflammatory Bowel Disease: A Literature Overview of Lifestyle, Psychological, and Environmental Risk Factors

Background: A significant concern for patients with Inflammatory Bowel Disease (IBD) is predicting and managing disease flares. While healthcare providers rely on biomarkers, providing conclusive patient advice remains challenging. This review explores the role of lifestyle, psychological health, and environmental exposures in the prediction and management of IBD flares. Methods: This review followed PRISMA guidelines (2020). A structured search was conducted in PubMed for articles published between 2012 and 2024, using free and Medical Subject Heading (MeSH) terms for predicting factors in IBD. Inclusion criteria included studies reporting primary data on modifiable clinical or environmental predictors of IBD relapse, excluding studies on post-operative investigations, treatment cessation, and pediatric or pregnant populations. The Mixed Method Appraisal Tool (MMAT) was used to assess the quality of the studies. Results: Out of 2287 identified citations, 58 articles were included. Several modifiable factors influencing disease flares were identified, including psychological stress, sleep disturbances, smoking, and nutrition. Poor sleep quality and mental health were linked to increased flare risks, while smoking was associated with higher relapse rates in Crohn's disease. Environmental exposures, such as heat waves and high-altitude regions, also contributed. Predictive models integrating clinical, lifestyle, and psychological factors showed promising accuracy but require further refinement. Limitations of this review include the potential for publication bias, variability in flare definitions, and limited sample sizes Conclusions: Key predictors of IBD flares include dietary factors, psychological stress, poor sleep quality, and pharmacological influences. Personalized approaches integrating these predictors can optimize disease control and improve patient outcomes.

FireVoxel: Interactive Software for Multi-Modality Analysis of Dynamic Medical Images

This article provides an overview of the FireVoxel software for quantitative analysis of medical images and its applications in the field. We describe FireVoxel's user interface, multi-layer design, dynamic parametric models, and several turn-key workflows. Additionally, we discuss its application in recent imaging projects. We outline basic image analysis tools such as segmentation, non-uniformity correction, and coregistration through a pictorial overview, with a focus on deformable coregistration and motion correction. Several example workflows and image-based dynamic modeling are also highlighted. Furthermore, we analyze peer-reviewed studies that utilized FireVoxel for image processing, categorizing published papers based on body structures/organs, image processing methods, and imaging modalities. For comparison, we searched the Ovid MEDLINE database to assess the general use of medical image analysis software. FireVoxel is used by over 3000 users worldwide, with 528 articles, including 413 in English, published in the past 15 years. MRI is the most commonly used imaging modality (78.2%), followed by CT (14.5%) and PET (7.3%). The most frequently used methods are dynamic modeling, segmentation, texture analysis, and coregistration. FireVoxel is commonly used in abdominal and genitourinary imaging studies, where it appears to fill a niche due to the lack of alternative software. The search of the Ovid MEDLINE suggests that quantitative medical imaging studies, on the other hand, focus on the brain and cardiovascular system. FireVoxel offers an effective set of quantitative tools, particularly for abdominal and genitourinary imaging, likely due to its ability to manage patient motion and correct for MR artifacts. The software is especially valuable for processing dynamic studies. The steady increase in publications utilizing FireVoxel reflects growing interest in this software and its relevance for image-based research.

Myopenia and body fat distribution in hospitalized ulcerative colitis patients: correlations with clinical characteristics and response to vedolizumab

Background

Ulcerative colitis (UC) patients often suffer from impaired nutritional conditions. However, there are few studies focused on muscle loss in UC patients as well as its impact on therapeutic response. This study aimed to investigate the prevalence of myopenia in hospitalized patients with active UC, analyze the relationship between body composition including both skeletal muscle and fat with clinical characteristics, and explore the association between body composition and clinical response to vedolizumab.

Methods

A retrospective cohort study was conducted in hospitalized patients with active UC in Peking Union Medical College Hospital from November 2014 to October 2022. Computed tomography (CT) scans were used to measure skeletal muscle area, visceral fat area (VFA), subcutaneous fat area (SFA), and intramuscular fat infiltration at the third lumbar vertebrae (L3) level. These measurements were standardized by height (m) squared. Myopenia was defined as a skeletal muscle index (SMI) < 44.77 cm2/m2 for males and <32.50 cm2/m2 for females. The VFA/SFA ratio (VSR) served as an indicator of visceral obesity, while intramuscular fat infiltration was evaluated using the mean Hounsfield Unit (HU) value of the L3 skeletal muscle section.

Results

A total of 457 patients were enrolled. The prevalence of myopenia was 49.7% in this cohort. Female patients had significantly higher levels of subcutaneous fat and intramuscular fat but a lower level of visceral fat than male patients. SMI and mean HU showed positive correlations with serum albumin (ALB) and negative correlations with serum high-sensitivity C-reactive protein (hsCRP), whereas VSR showed the opposite trend. Among the 92 patients who received vedolizumab treatment, myopenia was significantly associated with a lower clinical response rate, and this association remained significant after adjusting for vedolizumab duration, ALB, and hsCRP (OR = 3.458, 95% CI 1.238-9.659, p = 0.018). Visceral obesity, defined as VSR ≥ 75th centile of gender-specific VSR, tended to diminish the clinical response rate but did not reach statistical significance.

Conclusion

This study underscores the significance of assessing body composition in UC patients. Optimizing body composition should be considered an integral component of managing UC patients in the future.

DPP-IV as a potential candidate in anti-obesity and obesity-related diseases treatment

Along with social development and lifestyle changes, the number of overweight and obese patients worldwide is rising annually. Obesity is a chronic metabolic disease with complex etiology. Dipeptidyl peptidase IV (DPP-IV) is a novel adipokine with significantly elevated expression in the visceral fat of obese patients. DPP-IV is a molecule that regulates metabolic homeostasis and inflammatory processes. Through its enzymatic activity, it plays a significant part in achieving hypoglycemic and weight loss effects through various pathways. DPP-IV and DPP-IV inhibitors also have pleiotropic effects in modulating obesity-related diseases by reducing obesity-related inflammation, ameliorating inflammatory bowel disease (IBD), improving hepatic steatosis and lowering cardiovascular risk, and even decreasing the risk of novel coronavirus disease-19 (COVID-19). This paper reviews the mechanisms of action based on DPP-IV targets in obesity and metabolic homeostasis, as well as their active role in the treatment of chronic diseases associated with obesity.

Impact of Obesity and Metabolic Syndrome on IBD Outcomes

PURPOSE OF REVIEW

The recent surge in inflammatory bowel disease (IBD) cases has paralleled a significant rise in obesity and metabolic comorbidities rates. In this article, we explore the potential influence of obesity and associated metabolic comorbidities on disease progression, complications, treatment response, surgical outcomes, health economics, and the potential impact of obesity treatment on the course of IBD.

FINDINGS

Contrary to visceral adiposity, obesity does not consistently result in an increased risk of IBD-related complications. Patients with IBD have a higher risk of acute arterial events, likely linked to systemic inflammation. Substantial evidence suggests that obesity has a negative impact on the response to IBD treatment, with this effect being most thoroughly studied in biologics and immunomodulators. The rates of overall complications and post-operative infections are higher in patients who are obese. There are limited but promising data regarding the impact of weight loss techniques, including exercise, medications, and bariatric interventions, on the outcomes in IBD. Both obesity and diabetes have adverse effects on the overall quality of life and place an increased financial burden on the IBD population. A growing body of evidence indicates a connection between obesity and associated metabolic comorbidities and negative outcomes in IBD, yet further efforts are required to fully understand this relationship.

Heavy arch: from inflammatory bowel diseases to metabolic disorders

BACKGROUND

Metabolic disorders and inflammatory bowel diseases (IBD) have captured the globe during Westernisation of lifestyle and related dietary habits over the last decades. Both disease entities are characterised by complex and heterogeneous clinical spectra linked to distinct symptoms and organ systems which, on a first glimpse, do not have many commonalities in clinical practice. However, experimental studies indicate a common backbone of inflammatory mechanisms in metabolic diseases and gut inflammation, and emerging clinical evidence suggests an intricate interplay between metabolic disorders and IBD.

OBJECTIVE

We depict parallels of IBD and metabolic diseases, easily overlooked in clinical routine.

DESIGN

We provide an overview of the recent literature and discuss implications of metabolic morbidity in patients with IBD for researchers, clinicians and healthcare providers.

CONCLUSION

The Western lifestyle and diet and related gut microbial perturbation serve as a fuel for metabolic inflammation in and beyond the gut. Metabolic disorders and the metabolic syndrome increasingly affect patients with IBD, with an expected negative impact for both disease entities and risk for complications. This concept implies that tackling the obesity pandemic exerts beneficial effects beyond metabolic health.

Reviewing the impact of obesity on inflammatory bowel disease and considerations for optimizing management

PURPOSE OF REVIEW

This review examines the complex relationship between obesity and inflammatory bowel disease (IBD), encompassing their potentially shared pathogenesis, the impact of obesity on the natural history and treatment outcomes of IBD, and the management of obesity in the patient with IBD.

RECENT FINDINGS

Obesity represents a state of chronic inflammation that may not only contribute to IBD pathogenesis, but also influence disease progression, complications, and response to treatment. Increased visceral adiposity may carry negative prognostic implications for disease and treatment-specific outcomes. Antiobesity medications, endoscopic bariatric therapies, and even bariatric surgery may be effective and well tolerated in selected patients with IBD.

SUMMARY

The intersection of obesity and IBD presents a significant clinical challenge, with obesity influencing the natural history of IBD and potentially affecting treatment efficacy. As obesity prevalence among IBD patients rises, a tailored approach to management is crucial, taking into account the individualized risks and benefits of various treatment strategies, including lifestyle interventions, pharmacotherapy, endoscopic procedures, and bariatric surgery.

Factors contributing to flares of ulcerative colitis in North India- a case-control study

BACKGROUND

Ulcerative colitis is a relapsing and remitting disease that may be associated with flares. The causes of flares in the Indian setting are not well recognized.

METHODS

The present prospective case-control study was conducted at a single center in North India. Cases were defined as patients admitted for flare of ulcerative colitis, while controls were patients in remission enrolled from the outpatient department. The basis of the diagnosis of flare was a simple clinical colitis activity index (SCCAI) of ≥ 5 and endoscopic activity, while remission was based on SCCAI < 4 and a normal fecal calprotectin. A questionnaire evaluating recent infections, stress, drug intake (antibiotics, pain medication), adherence to therapy, and use of complementary and alternative therapy (CAM) was administered.

RESULTS

We included 84 patients (51 with flare and 33 in remission) with a median age of 38 years, of whom 47 (55.9%) were males. The two groups were similar for baseline parameters, including age (38, 23-50 and 38, 25.5-48.5 years), male gender (52.9% and 60.6%), extent of disease, extraintestinal manifestations (21.6% and 12.1%), use of 5-aminosalicylates (76.5% and 90.9%). The thiopurine use was lower in those having a flare (15.7% and 36.4%). Amongst the predictors of flare, the recent infections (39.2% and 30.3%), recent travel (31.4 and 27.3%), eating outside food (47.1% and 39.4%), consumption of milk products (88.2% and 75.8%), use of pain medication (43.1% and 33.3%) and recent stress (62.7% and 60.6%) were similar between cases and controls. The rates of antibiotic use (29.4% and 6.1%), lack of adherence (50.9% and 15.2%), and intake of CAM (70.6% and 33.3%) were higher in those with flare. Patients attributed a lack of adherence to the cost of therapy, presumed cure (due to lack of symptoms), and fear of adverse effects.

CONCLUSION

Lack of adherence to inflammatory bowel disease therapies and recent CAM and antibiotic intake was higher in patients with flares of UC. The study makes ground for educational intervention(s) promoting knowledge and adherence to IBD therapies.